Asymmetric cyanine dye

ABSTRACT

A compound represented by the general formula (I) or a salt thereof [wherein R 1 , R 2 , R 4 , and R 5  represent an alkyl group or an aryl group, and R 1  and R 2  and/or R 4  and R 5  may bind to each other to form a ring; R 3  represents hydrogen atom or sulfo group; R 6 , R 7 , R 8 , and R 9  represent hydrogen atom, a halogen atom, an alkyl group, an alkoxyl group, an amino group, nitro group or cyano group; X 1  and X 2  represent an alkyl group or an aryl group; m 1  to m 3  represents 0 or 1; L 1  to L 7  represent a methine group, and when two or more of methine groups among the aforementioned methine groups have a substituent, the substituents may bind to each other to form a ring; M represents hydrogen atom, a metal or a quaternary ammonium salt; and n represents an integer of 1 to 7 required to neutralize a charge]. The compound can be utilized as a novel cyanine dye useful as an infrared photosensitive dye that give no bad influence on photographic characteristics of a photographic emulsion and gives reduced residual color after development.

TECHNICAL FIELD

The present invention relates to asymmetric cyanines having asulfobenzindolenine and indolenine moieties.

BACKGROUND ART

In silver halide photographic light-sensitive materials, a photographicemulsion layer or another layer is often colored for the purpose ofabsorbing lights of a specific wavelength. When it is required tocontrol spectral composition of lights to be entered into a photographicemulsion layer, a colored layer is provided distant from a supportremoter than the photographic emulsion layer on a photographiclight-sensitive material. Such a colored layer is called as a filterlayer. In order to prevent blur of images, i.e., halation, which iscaused by lights scattered during or after transmission through aphotographic emulsion layer, then reflected by the interface of theemulsion layer and a support or a surface of the light-sensitivematerial on the side opposite to the emulsion layer side and reenteredinto the emulsion layer, a colored layer is provided between thephotographic emulsion layer and the support or on the side opposite tothe support and photographic emulsion layer. Such a colored layer iscalled as an antihalation layer. As for a laminated colorlight-sensitive material, antihalation layers may be provided betweenlayers. In order to prevent reduction of image sharpness due toscattering of lights in the photographic emulsion layer (this phenomenonis generally called as irradiation), the photographic emulsion layer mayalso be colored.

These layers that should be colored often consist of hydrophiliccolloid, and therefore a water-soluble dye is usually added to thelayers for the coloration. The dye needs to meet the followingrequirements.

(1) The dye has appropriate spectral absorption suitable for a purposeof use.

(2) The dye is inert in the sense of photographic chemistry. That is,the dye will not give any bad influence in a chemical sense on theperformance of silver halide photographic light-sensitive materials, forexample, reduction of sensitivity, regression of latent images or fog.

(3) The dye is bleached or removed by dissolution during photographicprocessing steps to leave no coloration harmful on processedphotographic light-sensitive materials.

(4) The dye has superior stability with passage of time in a solution ora photographic material.

As dyes satisfying these requirements, many dyes are known which absorbvisible lights or ultraviolet rays. These dyes are suitable for an imageimprovement purpose in conventional photographic elements sensitized fora wavelength of 700 nm or less, and in particular, triarylmethane andoxonol dyes are widely used in relation to this purpose.

For recording materials sensitized for an infrared wavelength, e.g.,photographic light-sensitive materials as recording materials for outputof a near-infrared laser, a development of an antihalation dye andirradiation neutralizing dye that absorb lights in an infrared region ofa spectrum has recently been desired. For example, as one of lightexposure methods of such photographic light-sensitive materials asdescribed above, the so-called scanner type image forming method isknown, which comprises the steps of scanning an original and exposing asilver halide photographic light-sensitive material on the basis ofimage signals obtained by the scanning, and then forming a negativeimage or positive image corresponding to the image of the original. Inthis method, a semiconductor laser is most preferably used as a lightsource for the scanner type recording. The semiconductor laser iscompact and inexpensive, and its modulation is easy. Moreover, saidlaser has a longer lifetime compared with other He—Ne lasers, argonlasers and the like. Furthermore, since the aforementioned laser emits alight in an infrared region, it has an advantage that when alight-sensitive material having photosensitivity for an infrared regionis used, a bright is available and handling workability is improved.

However, since no appropriate dye is available that absorb lights in aninfrared region of a spectrum and satisfies the aforementionedrequirements (1), (2), (3) and (4), especially the requirements (2) and(3), there are a few superior light-sensitive materials with highphotosensitivity for the infrared region in which halation andirradiation are prevented. Therefore, the advantageous characteristicsof the semiconductor laser having the excellent performance as mentionedabove cannot be fully enjoyed.

As state of the art relating to asymmetric cyanines having abenzindolenine moiety having one or two sulfo groups and an indoleninemoiety, cyanine dyes having five or more acidic substituents in amolecule are disclosed in Japanese Patent Unexamined Publication (KOKAI)(Hei) No. 5-307233. However, the substituents on the indolenine moietyare limited to sulfo group and carboxyl group. No cyanine dye having asubstituent on a methine chain has been known so far.

DISCLOSURE OF THE INVENTION

An object of the present invention is to provide a dye that meets theaforementioned requirements (1), (2), (3) and (4). More specifically,the object of the present invention is to provide a novel cyanine dyeuseful as an infrared photosensitive dye that does not give any badinfluence on photographic characteristics of a photographic emulsion andgives reduced residual color after development. Moreover, it is also anobject of the present invention to provide a silver halide photographiclight-sensitive material containing said compound.

The inventors of the present invention conducted various researches toachieve the aforementioned objects. As a result, they found that thecompounds represented by the following general formula (I) and saltsthereof had the aforementioned characteristics and were useful for theproduction of silver halide photographic light-sensitive materials. Thepresent invention was achieved on the basis of the above findings.

The present invention thus provides compounds represented by thefollowing general formula (I) and salts thereof:

wherein R¹, R², R⁴, and R⁵ independently represent a substituted orunsubstituted alkyl group having 1 to 10 carbon atoms or a substitutedor unsubstituted aryl group, and R¹ and R² and/or R⁴ and R⁵ may bind toeach other to form a ring; R³ represents hydrogen atom or sulfo group;R⁶, R⁷, R⁸, and R⁹ independently represent hydrogen atom, a halogenatom, a substituted or unsubstituted alkyl group having 1 to 6 carbonatoms, a substituted or unsubstituted alkoxyl group having 1 to 6 carbonatoms, a substituted or unsubstituted amino group, nitro group or cyanogroup, and two of adjacent groups selected from the group consisting ofR⁶, R^(7,) R⁸ and R⁹ may bind to each other to form a ring; X¹ and X²independently represent a substituted or unsubstituted alkyl grouphaving 1 to 10 carbon atoms or a substituted or unsubstituted arylgroup; m¹ represents 0 or 1; m² represents 0 or 1; m³ represents 0 or 1;L¹, L², L³, L⁴, L⁵, L⁶, and L⁷ independently represent a substituted orunsubstituted methine group, and when two or more of methine groupsamong the aforementioned methine groups have a substituent, thesubstituents may bind to each other to form a ring; M representshydrogen atom, a metal or a quaternary ammonium salt; and n representsan integer of 1 to 7 required to neutralize the charge.

In the aforementioned general formula (I), it is preferred that m¹, m²and m³ all represent 1, and it is preferred that R³ is sulfo group. Itis more preferred that m¹, m² and m³ all represent 1, and R³ is sulfogroup. Preferred compounds represented by the aforementioned generalformula (I) or salts thereof include the compounds or salt thereofwherein at least one of L¹, L², L³, L⁴, L⁵, L⁶, and L⁷ is a methinegroup having a substituent, and more preferred compounds represented bythe aforementioned general formula (I) or salts thereof are thecompounds and salts thereof wherein m¹, m² and m³ all represent 1, andat least one of L¹, L², L³, L⁴, L⁵, L⁶, and L⁷ is a methine group havinga substituent.

From another aspect, the present invention provides silver halidephotographic light-sensitive materials containing the compoundsrepresented by the aforementioned general formula (I) or salts thereof.Moreover, the present invention also provides use of the compoundsrepresented by the aforementioned general formula (I) or salts thereoffor the manufacture of silver halide photographic light-sensitivematerials.

BEST MODE FOR CARRYING OUT THE INVENTION

The alkyl group having 1 to 10 carbon atoms represented by R¹, R², R⁴,or R⁵ may be a straight, branched, or cyclic alkyl group or an alkylgroup consisting of a combination thereof (in the specification, otheralkyl groups and alkyl moieties of substituents containing the alkylmoiety have the same meaning unless otherwise specifically mentioned).As the unsubstituted alkyl group, for example, methyl group, ethylgroup, propyl group, butyl group, and hexyl group can be used. Thenumber, types, and substituting positions of the substituents whichexist on the substituted alkyl group are not particularly limited. Asthe substituted alkyl group, for example, a sulfoalkyl group, acarboxylalkyl group, a hydroxyalkyl group, an alkoxyalkyl group, anaminoalkyl group, a halogenoalkyl group, a cyanoalkyl group, anaryl-substituted alkyl group, and a heteroaryl-substituted alkyl groupcan be used.

The aryl group represented by R¹, R², R⁴, or R⁵ may be a monocyclic arylgroup or condensed ring aryl group, and a 6- to 14-membered aryl group,more preferably a 6- to 10-membered aryl group, can be preferably used(in the specification, aryl groups and aryl moieties of substituentscontaining the aryl moiety have the same meaning unless otherwisespecifically mentioned). Preferred examples of the aryl group includephenyl group and naphthyl group, and a more preferred example includesphenyl group. As the substituted aryl group, a sulfophenyl group, ahydroxyphenyl group and an aminophenyl group can be used.

R¹ and R², and R⁴ and R⁵ may bind to each other to form a ring. Examplesof the ring to be formed include, for example, cyclopentyl ring,cyclohexyl ring and the like. R¹, R², R⁴, and R⁵ preferably representmethyl group or ethyl group, more preferably methyl group. As the alkylgroup or aryl group represented by X¹ or X², the alkyl groups and arylgroups explained for R¹, R², R⁴, and R⁵ can be used.

When the alkyl group, alkoxyl group, or amino group represented by R⁶,R⁷, R⁸, or R⁹ has a substituent, for example, a halogen atom selectedfrom fluorine atom, chlorine atom, bromine atom and iodine atom; a C₁₋₆alkyl group such as methyl group, ethyl group, n-propyl group, isopropylgroup, n-butyl group, sec-butyl group and tert-butyl group; ahalogenated C₁₋₆ alkyl group such as trifluoromethyl group; a C₁₋₆alkoxyl group such as methoxy group, ethoxy group, n-propoxy group,isopropoxy group, n-butoxy group, sec-butoxy group and tert-butoxygroup; a C₁₋₆ alkylenedioxy group such as methylenedioxy group andethylenedioxy group; unsubstituted amino group; a C₁₋₆ alkyl-substitutedamino group such as methylamino group, dimethylamino group andethylamino group; nitro group; cyano group and the like can be used asthe substituent. For example, 1 to 4 of the aforementioned substituentsmay exist. Positions of the substituents are not limited, and when twoor more substituents exist, they may be the same or different. Two ofadjacent groups selected from the group consisting of R⁶, R⁷, R⁸, and R⁹may bind to each other to form a ring. The ring to be formed may besaturated or unsaturated, and the ring may be a hydrocarbonic orheterocyclic ring. For example, R⁶ together with R⁷, R⁷ together withR⁸, and R⁸ together with R⁹ may bind to form an aromatic ring such asbenzene ring or an aromatic heterocyclic ring such as pyridine ring.

L¹, L², L³, L⁴, L⁵, L⁶, and L⁷ independently represent a substituted orunsubstituted methine group. Symbols m¹, m², and m³ independentlyrepresent 0 or 1, and it is preferred that m¹, m² and m³ allrepresent 1. Examples of the substituent of the methine group include asubstituted or unsubstituted alkyl group, a halogen atom, a substitutedor unsubstituted aryl group, a lower alkoxyl group and the like.Specific examples of the substituted aryl group include 4-chlorophenylgroup and the like. The lower alkoxyl group is preferably an alkoxylgroup having 1 to 6 carbon atoms, and the group may be a linear orbranched alkoxyl group. Specific examples include methoxy group, ethoxygroup, propoxy group, butoxy group, tert-butoxy group, pentyloxy groupand the like, and preferred are methoxy group and ethoxy group. As thesubstituent of the methine group, methyl group and phenyl group can bepreferably used.

When the methine group represented by L¹, L², L³, L⁴, L⁵, L⁶, or L⁷ hasa substituent, substituents on the methine groups may bind together toform a ring. Preferably, substituents on the methine groups may bindtogether to form a ring including three of continuous methine groupsselected from L¹, L², L³, L⁴, L⁵, L⁶, and L⁷. Moreover, the ring formedas described above may further form a condensed ring with a ringincluding three of continuous methine groups selected from L¹, L², L³,L⁴, L⁵, L⁶, and L⁷. Examples of the compounds, wherein substituents onthe methine groups bind together to form a ring including three ofcontinuous methine groups selected from L¹, L², L³, L⁴, L⁵, L⁶ and L⁷,include the compounds wherein a 4,4-dimethylcyclohexene ring includingL³, L⁴, and L⁵ is formed. A particularly preferred partial structureconsisting of a conjugated methine chain, including a ring constitutedby methine groups selected from L¹, L², L³, L⁴, L⁵, L⁶ and L⁷, is agroup represented by the following general formula (a).

wherein Z represents a nonmetallic atom group required to form a 5- or6-membered ring, and A represents hydrogen atom or a monovalent group.

Examples of the nonmetallic atom group required to form a 5- or6-membered ring, which is represented by Z, include, for example, carbonatom, nitrogen atom, oxygen atom, hydrogen atom, sulfur atom, a halogenatom (fluorine atom, chlorine atom, bromine atom, iodine atom) and thelike. Examples of the 5- or 6-membered ring in the partial structurerepresented by the general formula (a) include, for example,cyclopentene ring, cyclohexene ring, 4,4-dimethylcyclohexene ring andthe like, and preferred are cyclohexene ring and cyclopentene ring.

Examples of the monovalent group represented by A include a substitutedor unsubstituted alkyl group, a substituted or unsubstituted aryl group,a substituted or unsubstituted aralkyl group, a substituted orunsubstituted lower alkoxyl group, a substituted or unsubstituted aminogroup, a substituted or unsubstituted alkylcarbonyloxy group (acetoxygroup and the like), a substituted or unsubstituted alkylthio group, asubstituted or unsubstituted arylthio group, cyano group, nitro group, ahalogen atom and the like.

Specific examples of the aralkyl group represented by A include benzylgroup, 2-phenylethyl group, 3-phenylpropyl group and the like, andexamples of the substituent of the aralkyl group include, for example,sulfo group, carboxyl group, hydroxyl group, a substituted orunsubstituted alkyl group, an alkoxyl group, a halogen atom and thelike. Specific examples of the amino group having a substituentrepresented by A include, for example, an alkylamino group (methylaminogroup, ethylamino group and the like), a dialkylamino group(dimethylamino group, diethylamino group and the like), phenylaminogroup, diphenylamino group, methylphenylamino group and a cyclic aminogroup (morpholino group, imidazolidino group, ethoxycarbonylpiperazinogroup and the like), and when these groups have a substituent, sulfogroup, carboxyl group and the like may be used as the substituent.Specific examples of the alkylthio group represented by A includephenylthio group, naphthylthio group and the like, and specific examplesof the substituent of the alkylthio group include sulfo group, carboxylgroup and the like.

Preferred examples of the monovalent group represented by A includephenylamino group, diphenylamino group, ethoxycarbonylpiperazino group,an arylthio group and the like. Symbol A is preferably a monovalentgroup having a sulfonic acid group, and it is most preferred that A isselected from the group consisting of phenylamino group, diphenylaminogroup, ethoxycarbonylpiperazino group and carboxyphenylthio group andhas sulfonic acid group.

Symbol M represents hydrogen atom, a metal or a quaternary ammoniumsalt. Examples of the metal include an alkali metal such as sodium andpotassium, an alkaline earth metal such as magnesium and calcium, andexamples of the ammonium salt include an ammonium salt, triethylammoniumsalt, tributylammonium salt, a salt of an amino acid such as lysine andarginine. However, M is not limited to these examples.

The compounds of the present invention may have one or more asymmetriccarbons depending on the types of substituents. Furthermore, a sulfuratom may serve as an asymmetric center. Arbitrary optical isomers basedon one or more asymmetric carbons in optically pure forms, any mixturesof such optical isomers, racemates and diastereoisomers based on two ormore asymmetric carbon atoms, any mixtures of such diastereoisomers andthe like all fall within the scope of the present invention.

Specific examples of the compounds of the present invention will beshown below. However, the present invention is not limited to thefollowing compounds.

The cyanine dyes represented by the aforementioned general formula (I)can be synthesized according to the known methods for producing cyaninedye compounds described in F. M. Hamer, The Cyanine Dyes and RelatedCompounds, John Wiley and Sons, New York, 1964; Cytometry, 11,pp.416-430, 1990; Cytometry, 12, pp.723-730, 1990; Bioconjugate Chem.,4, pp.105-111, 1993; Anal. Biochem., 217, pp.187-204, 1994; Tetrahedron45, pp.4845-4866, 1989; European Patent Publication Nos. 0591820A1 and0580145A1, and they can also be semisynthesized from commerciallyavailable cyanine dyes by a suitable known procedure. More specifically,they can be synthesized by a reaction of a dianyl compound and aheterocyclic quaternary salt.

The method for producing the cyanine dyes represented by theaforementioned general formula (I) is not particularly limited, and theycan be synthesized via various kinds of synthetic routes. Specificproduction methods are disclosed in the examples of the specificationfor typical examples of the compounds of the present invention, andtherefore, those skilled in the art can synthesize compounds fallingwithin the scope of the aforementioned general formula (I) by referringto the methods described in the examples, and by adding suitablealterations or modifications to the methods, if necessary, and further,by suitably selecting starting materials and regents. In the synthesis,one or more steps of various kinds of condensations, additions,oxidations, reductions and the like can be combined. These are detailedin publications. For example, various kinds of methods described in“Jikken Kagaku Koza (Lecture of Experimental Chemistry)”, published byMaruzen Co., Ltd., each separate volume included in each of the first to4th editions can be used) as unit operations and raw material compoundscan be suitably used.

For example, in these production methods, when a defined group changesunder conditions of a desired reaction step, or it is unsuitable forcarrying out a desired reaction step, the step may be efficientlycarried out by using methods commonly used in the synthetic organicchemistry such as means of protection and deprotection of a functionalgroup or treatments of oxidation, reduction, hydrolysis and the like Inthe aforementioned steps, synthetic intermediates and target compoundscan be separated and purified by purification methods commonly used inthe synthetic organic chemistry, for example, filtration, extraction,washing, desiccation, concentration, recrystallization, various kinds ofchromatographies and the like Synthetic intermediates can also be usedfor subsequent steps without performing particular isolation.

The method of incorporating the compounds represented by theaforementioned general formula (I) or salts thereof according to thepresent invention into silver halide photographic light-sensitivematerials is not particularly limited, and they can be suitablyincorporated by ordinary means used in the field of silver halidephotographic light-sensitive material. Performance of silver halidephotographic light-sensitive materials containing the compounds or saltthereof according to the present invention can also be confirmed byordinary methods. Specific means for the evaluation are disclosed intest examples in the following examples, and therefore, by referring tothe test examples, those skilled in the art can appropriately use thecompounds or salt thereof according to the present invention forproduction of silver halide light-sensitive materials and therebyproduce silver halide photographic light-sensitive materials withdesired performance.

EXAMPLES

The present invention will be more specifically explained by referringto the following examples. However, the scope of the present inventionis not limited to these examples. The numbers of the compounds used inthe examples correspond to the compound numbers of the preferredcompound exemplified above.

Example 1

Synthesis of Compound 1

The synthetic route of Compound 1 is shown below.

Synthesis of Intermediate 1

4,5-Disulfobenzindolenine (1) (7.9 g, 0.02 mol), triethylamine (4.1 g,0.04 mol) and sulfolane (10 mL) were stirred for 10 minutes with heatingat 100° C., then added with 1,4-butanesultone (5.5 g, 0.04 mol) andstirred for 12 hours with heating at 150° C. After the reaction, thereaction mixture was added with 2-propanol (100 mL) and cooled to roomtemperature, and the produced crystals were collected by filtration toobtain Intermediate 1.

Amount: 4.9 g (yield: 35%)

Synthesis of Intermediate 2

Intermediate 1 (1.06 g, 1.5 mmol) obtained above and1,7-diaza-1,7-diphenyl-1,3,5-heptatriene monohydrochloride (0.43 g, 1.5mmol) were dissolved in methanol (10 mL), added with triethylamine (0.63mL, 4.5 mmol) and acetic anhydride (0.84 g, 9.0 mmol) and stirred for 10minutes at room temperature. The reaction mixture was added dropwise toethyl acetate (200 mL), and the produced crystals were collected byfiltration. The crystals were passed through a column filled with asodium sulfonate type cation exchange resin, Amberlite IR-120B (producedby ORGANO CORP., developing solvent: methanol) and after the solvent wasevaporated under reduced pressure, further purified by columnchromatography using Sephadex (LH-20, produced by Pharmacia, developingsolvent: methanol) to obtain Intermediate 2.

Amount: 0.42 g (yield: 38%)

Synthesis of Compound 1

Intermediate 3 (120 mg, 0.2 mmol) obtained above and1-(3-sulfopropyl)-2,3,3-trimethylindolenium (2) (90 mg, 0.3 mmol) weredissolved in a mixed solvent of methanol (3 mL) and water (2 mL), addedwith acetic anhydride (100 mg, 1.0 mmol) and sodium acetate (80 mg, 1.0mmol) and stirred overnight at room temperature. The reaction mixturewas purified by column chromatography using Sephadex (LH-20, produced byPharmacia, developing solvent: methanol) and then further purified byreverse phase preparative TLC (produced by Merck, developing solvent:methanol:water=1:1) to obtain Compound 1.

Amount: 12 mg (yield: 8%)

λ max (DMSO)=767 nm (ε=1.1×10⁵)

Test Example 1

1. Preparation of Silver Halide Emulsion

To a vessel containing gelatin (34 g) dissolved in water (850 mL) andwarmed to 65° C., sodium chloride (1.7 g), potassium bromide (0.1 g) andCompound (A) (HO(CH₂)₂—S—(CH₂)₂—S—(CH₂)₂—OH, 70 mg) were added. Then, anaqueous solution (500 mL) containing silver nitrate (170 g), potassiumhexachloroiridate(III) in such an amount that a molar ratio of iridiumon the basis of silver halide in the completed emulsion became 5×10⁻⁷,and an aqueous solution (500 mL) containing sodium chloride (12 g) andpotassium bromide (98 g) were added by the double jet method to preparemonodispersed cubic silver chlorobromide grains having a mean grain sizeof 0.35 μm. After desalting, the resulting emulsion was added withgelatin (50 g), adjusted to pH 6.5 and pAg 8.1, then added with sodiumthiosulfate (2.5 mg) and chloroauric acid (5 mg). The emulsion waschemically sensitized at 65° C., then added with4-hydroxy-6-methyl-1,3,3a,7-tetrazaindene (0.2 g) and solidified byrapid cooling (Emulsions A).

Then, monodispersed cubic silver chlorobromide grains having a meangrain size of 0.3 μm were prepared in the same manner as that used forEmulsion A, except that the aforementioned gelatin solution was warmedto 40° C. After desalting, the emulsion was added with gelatin (50 g)and adjusted to pH 6.5 and pAg 8.1. This emulsion was added with sodiumthiosulfate (2.5 mg) and chloroauric acid (5 mg), chemically sensitizedat 65° C., then added with 4-hydroxy-6-methyl-1,3,3a,7-tetrazaindene(0.2 g) and solidified by rapid cooling to prepare Emulsions B.

2. Preparation of Coating Solution for Emulsion Layer

Emulsion A and Emulsion B were mixed at a mass ratio of 1:1 and addedwith the additives mentioned below in the indicated amounts per 1 moleof the silver halide to prepare a coating solution for emulsion layer.(Composition of coating solution for emulsion layer) a. Spectralsensitization dye [2] 1.0 × 10⁻⁴ mol b. Supersensitizer [3] 0.7 × 10⁻³mol c. Storage improver [4] 1 × 10⁻³ mol d. Polyacrylamide (molecularweight: 40,000) 7.5 g e. Dextran 7.5 g f. Trimethylolpropane 1.6 g g.Polystyrenesulfonate Na 1.2 g h. Poly(ethyl acrylate/methacrylic acid)latex  12 g i. N,N′-Ethylenebis(vinylsulfoneacetamide) 3.0 g j.1-Phenyl-5-mercaptotetrazole  50 mg Spectral sensitization dye [2]

Supersensitizer [3]

Storage improver [4]

3. Preparation of Coating Solution for Surface Protective Layer forEmulsion Layer

A vessel was warmed at 40° C., and the additives in the compositionmentioned below were added to prepare a coating solution. (Compositionof coating solution for surface protective layer for emulsion layer) a.Gelatin  100 g b. Polyacrylamide (molecular weight: 40,000)   12 g c.Polystyrenesulfonate Na (molecular weight: 600,000)  0.6 g d.N,N′-Ethylenebis(vinylsulfoneacetamide)  2.2 g e. Poly(methylmethacrylate) microparticles  2.7 g  (average particle size: 2.0 μm) f.Sodium t-octylphenoxyethoxyethanesulfonate  1.8 g g.C₁₆H₃₃O—(CH₂CH₂O)₁₀—H  4.0 g h. Sodium polyacrylate  6.0 g i. C₈F₁₇SO₃K  70 mg j. C₈F₁₇SO₂N(C₃H₇)(CH₂CH₂O)₄(CH₂)₄—SO₃Na   70 mg k. NaOH (1N)  6 mL l. Methanol   90 mL m. Antifoggant compound X 0.06 g

4. Preparation of Coating Solution for Back Layer

A vessel was warmed at 40° C., and the additives in the compositionmentioned below were added to prepare a coating solution for back layer.(Composition of coating solution for back layer) a. Gelatin  100 g b.Dye [A, Compound 1 of the present invention]  4.2 g c. Sodiumpolystyrenesulfonate  1.2 g d. Poly(ethyl acrylate/methacrylic acid)latex   5 g e. N,N′-Ethylenebis(vinylsulfoneacetamide)  4.8 g f.Antifoggant compound X 0.06 g g. Dye [B]  0.3 g h. Dye [C] 0.05 g i.Colloidal silica   15 g Dye [B]

Dye [C]

5. Preparation of Coating Solution for Back Surface Protective Layer

A vessel was warmed at 40° C., and the additives in the compositionmentioned below were added to prepare a coating solution. (Compositionof coating solution for back surface protective layer) a. Gelatin 100 gb. Sodium polystyrenesulfonate 0.5 g c.N,N′-Ethylenebis(vinylsulfoneacetamide) 1.9 g d. Poly(methylmethacrylate) microparticles 4 g (average particle size: 4.0 μm) e.Sodium t-octylphenoxyethoxyethanesulfonate 2.0 g f. NaOH (1 N) 6 mL g.Sodium polyacrylate 2.4 g h. C₁₆H₃₃O—(CH₂CH₂O)₁₀—H 4.0 g i. C₈F₁₇SO₃K 70mg j. C₈F₁₇SO₂N(C₃H₇)(CH₂CH₂O)₄(CH₂)₄—SO₃Na 70 mg k. Methanol 150 mL l.Antifoggant compound X 0.06 g6. Preparation of Photographic Material

The aforementioned coating solution for back layer surface protectivelayer was coated together with the aforementioned coating solution forback layer on a polyethylene terephthalate support in such an amountthat the total coated gelatin amount should become 3 g/m². Subsequently,on the opposite side of the support, the aforementioned coating solutionfor emulsion layer and coating solution for surface protective layerwere coated in such amounts that the coated amount of Ag should become2.3 g/m² and the coated gelatin amount in the surface protective layershould become 1 g/m² (Photographic material 1). Furthermore,Photographic material 2 was prepared in the same manner except that acompound of the present invention (Compound 1) was used instead of Dye[A] in the same mass.

Photographic materials 1 to 4 were exposed for 10⁻⁷ second by scanningusing a semiconductor laser emitting a light of 783 nm and developed byusing a roller transportation type automatic processor with Developer[I] and Fixer [I] mentioned below. The times for development, fixing,washing with water, and drain and desiccation were 7 seconds, 7 seconds,4 seconds and 11 seconds, respectively. The transportation speed was3000 mm/minute. Composition of Developer [I] Potassium hydroxide 29 gSodium sulfite 31 g Potassium sulfite 44 g Ethylenetriaminetetraaceticacid 1.7 g Boric acid 1 g Hydroquinone 30 g Diethylene glycol 29 g1-Phenyl-3-pyrazolidone 1.5 g Glutaraldehyde 4.9 g 5-Methylbenzotriazol60 mg 5-Nitroindazole 0.25 g Potassium bromide 7.9 g Acetic acid 18 gWater up to 1000 mL pH 10.3

Composition of Fixer [I] Ammonium thiosulfate 140 g Sodium sulfite 15 gDisodium ethylenediaminetetraacetate dihydrate 20 mg Sodium hydroxide 7g Aluminum sulfate 10 g Boric acid 10 g Sulfuric acid 3.9 g Acetic acid15 g Water up to 1000 mL pH 4.30

Image quality was evaluated according to five-level evaluation criteriafrom 1 (there are many fringes and image quality is very bad) to 5(there is no fringe and a sharp image is obtained). Residual color wasevaluated according to five-level evaluation criteria from 1 (very muchresidual color remains) to 5 (there is no residual color). As a result,Photographic material 1 (containing Compound 1 of the present invention)gave results of level 5 for image quality and level 4 for residual colorafter processing. From these results, it is clearly understood that asilver halide photographic light-sensitive material containing thecompound of the present invention has advantageous effects in that thematerial gives images with excellent quality after exposure with a lighthaving a wavelength of infrared region and development, and gives littlereduced residual color after development.

Industrial Applicability

The compounds of the present invention are useful for production ofsilver halide photographic light-sensitive materials, and they can beincorporated in, for example, a hydrophilic colloid layer and the likeWhen the compounds of the present invention are used, silver halidephotographic light-sensitive materials can be provided which give imageswith favorable quality and reduced residual color after developmentafter light exposure at a wavelength of the infrared region anddevelopment.

1. A compound represented by the following general formula (I) or a saltthereof:

wherein R¹, R², R⁴, and R⁵ independently represent a substituted orunsubstituted alkyl group having 1 to 10 carbon atoms or a substitutedor unsubstituted aryl group, and R¹ and R² and/or R⁴ and R⁵ may bind toeach other to form a ring; R³ represents a hydrogen atom or a sulfogroup; R⁶, R⁷, R⁸, and R⁹ each independently represents a hydrogen atom,a halogen atom, a substituted or unsubstituted alkyl group having 1 to 6carbon atoms, a substituted or unsubstituted alkoxyl group having 1 to 6carbon atoms, a substituted or unsubstituted amino group, nitro group orcyano group, and two of adjacent groups selected from the groupconsisting of R⁶, R⁷, R⁸, and R⁹ may bind to each other to form a ring;X¹ and X² each independently represents a substituted or unsubstitutedalkyl group having 1 to 10 carbon atoms or a substituted orunsubstituted aryl group; m¹ represents 0 or 1; m² represents 0 or 1; m³represents 0 or 1; L¹, L², L³, L⁴, L⁵, L⁶, and L⁷ each independentlyrepresents a substituted or unsubstituted methine group, and when two ormore of methine groups among the aforementioned methine groups have asubstituent, the substituents may bind to each other to form a ring; Mrepresents a hydrogen atom, a metal or a quaternary ammonium salt; and nrepresents an integer of 1 to 7 required to neutralize a charge.
 2. Thecompound or a salt according to claim 1, wherein m¹, m², and m³ allrepresent
 1. 3. The compound or a salt according to claim 1 or 2,wherein R³ is a sulfo group.
 4. The compound or a salt according toclaim 1 or 2, wherein at least one of L¹, L², L³, L⁴, L⁵, L⁶, and L⁷ isa methine group having a substituent.
 5. The compound or a saltaccording to claim 3, wherein at least one of L¹, L², L³, L⁴, L⁵, L⁶,and L⁷ is a methine group having a substituent.